Lui said the government has already invested heavily in improving public transport services by supporting Singapore’s rail network and setting aside $1.1 billion to help get more buses serving the roads in Singapore.

“The further improvements we are thinking of, such as even more improved service levels, which will require amongst others more bus drivers and higher salaries, are costly,” he wrote. “They come on top of various costs increases to the operators, such as rising energy costs. Somebody has to pay for these costs, either commuters in fares, or taxpayers in government subsidies, or the PTOs.

“The proper balance is something we have to study very carefully,” he continued. “But we should not simply take the populist approach of avoiding any fare increases completely, and just push it onto the PTOs or rely on more and more government subsidies.”

Lui added further that this scenario would not only require more public funds, but also would give operators less incentive to be efficient and to provide good services to commuters.

“The purpose of fare increases is not to boost the short-term profits of PTOs (public transport operators),” he wrote. “It is also not just to improve salaries of bus drivers but to improve service to commuters while keeping public transport operations commercially viable.”

He explained that this is why the government will work with PTOs to ensure that part of the additional revenue earned from any fare increments will be re-invested into improvements for the public transport system, either in terms of what he calls “hardware” — more buses, trains and better signalling systems — or “software” — better employment terms and salaries for staff, including not just bus drivers and train operators, but also for maintenance and service personnel.

Lui also stressed the government’s commitment to keeping public transport affordable for low- to middle-income groups, the disabled and other vulnerable parties, adding that he hopes to see the public transport council devise ways to help these groups as part of its next recommendation for fare adjustment.

“The bottom line is this: this is not just a matter of raising fares to pay bus drivers higher salaries,” he wrote. “It is a matter of all the stakeholders — the PTOs, the government, and yes, commuters too — coming together to ensure we enjoy a reliable, high-quality and affordable public transport system.”

Earlier this week, 84 per cent of some 3,000 Yahoo! Singapore readers voted against having to pay more in fares in exchange for higher bus drivers' salaries, saying that operators should absorb these additional costs.